I chagne my oil in my 02 dodge 1500 QC with the 4.7L magnum every 3k - 3.5k miles due to my driving habits. 80% of those miles are less 2 miles to work. I am looking for a more robust oil then the Valvoline Durablend I have been using. I like Valvoline but it is a unremarkable oil. its SL/CL rated so I'm confident it wil last the 3k miles but I want to maybe extend to 5k and no more. is Delo 400 a good alternative? Sugesstions? Oh, should mention i use 5w-30 winter 10w-30 summer. Not even sure if i can get a delo in a 30wt. Also keep in mind with suggestions im not interested in a synthetic so much as for me it might be a waist of money. due to short drain intervels.